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<h1 align="center"><span class="pagetitle">Opera CSS Extensions</span></h1>
<div align="center"><b><a href="../../../misc/suppkey.htm">Support Key:</a></b>
[<b><i class="fs">O4</i></b>]<br>
<font size=2>= <span class="sitetitle">Index DOT Css</span> by <a 
href="../../../misc/email.htm">Brian Wilson</a> =</font></div>

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<dl>
<dt><big><b class="mainheading">What Are They?</b></big>
    <dd>Many browser makers have been <a href="http://lists.w3.org/Archives/Public/www-style/2002Jan/0094.html">following
        a convention</a> of using a dash
        character ("-") as a prefix for proprietary CSS properties...Opera follows
        this convention with a few XML-specific CSS properties created to enable
        some functionalities in their XML rendering of WML, mail and news.
        (BTW, Microsoft's Internet Explorer for Win32 doesn't adhere to this
        convention - they have chosen to name their proprietary properties
        anything they feel like, which may create compatibility problems later on.)
        <br><br>

        These proprietary properties allow replaced element images and hyperlinking
        behavior to be included in general XML documents. An author could use
        XHTML for this purpose, but for cases where that is not possible, these
        Opera CSS properties add this basic functionality from HTML to any XML
        document. (NOTE: These properties only work on non-HTML/XHTML documents.)
        <br><br>

        Should you use these proprietary CSS properties and values? Opera suggests
        that you should not. But, as long as you keep in mind that Opera is the
        only browser that can utilize these properties, hanging yourself because
        of possible cross-browser incompatibilities should be a choice that anyone
        has in their development toolbox. Of course, Opera is making things as 
        difficult as possible for authors to use these properties: with every browser
        version they have changed the names of these properties every time. 
        I attempt to list these properties here mostly for completeness sake.
        <br><br>

        The following information is mostly from <a href="http://www.opera.com/docs/specs/">Opera's
        documentation</a>, quoted where directly referenced.</dd>
</dl>

<dl>
<dt><big><b class="mainheading">Proprietary Opera CSS Properties</b></big>
<dt><b class="subheading">-o-replace</b></dt>
    <dd><b class="l3heading">Support:</b> [<b><i class="fs">O7</i></b>] 
    (See note below about the previous names for this property in older Opera versions)</dd>
    <dd><b class="l3heading">Inherited:</b> No</dd>
    <dd><b class="l3heading">Allowed Values:</b><br>
        - <b>None</b>: [DEFAULT] Element is not a replaced element.<br>
        - <b>attr([ATTRIBUTE])</b>:  Element will be replaced by the
        contents of the URL specified in the [ATTRIBUTE] value.</dd>
    <dd><b class="l3heading">Purpose:</b><br>
        Primarily used to to display images in XML documents...<br>
        "This property declares the element to be replaced or not. If replaced,
        the attr() function is used to point to the attribute where the URI to
        the content can be found."</dd>

<dt><b class="subheading">-o-set-link-source</b></dt>
    <dd><b class="l3heading">Support:</b> [<b><i class="fs">O7</i></b>]
    (See note below about the previous names for this property in older Opera versions)</dd></dd>
    <dd><b class="l3heading">Inherited:</b> No</dd>
    <dd><b class="l3heading">Allowed Values:</b><br>
        - <b>None</b>: [DEFAULT] Do not set a link source for this element.<br>
        - <b>attr([ATTRIBUTE])</b>: Use the value of the [ATTRIBUTE] attribute as the link-source<br>
        - <b>[URL]</b>: Use the specified URL as the link-source<br>
        - <b>[String]</b>: Use the specified string as the link-source<br>
        - <b>content()</b>:  Unknown - This is from Opera's documentation, but there
          are no examples listed to aid in understanding this usage</dd>
    <dd><b class="l3heading">Purpose:</b><br>
        Primarily used to set the destination URL for a hyperlink in XML documents...<br>
        "This property sets the value of the 'link' variable which can later be used
        to generate a link through the '-o-use-link-source' property." </dd>

<dt><b class="subheading">-o-use-link-source</b></dt>
    <dd><b class="l3heading">Support:</b> [<b><i class="fs">O7</i></b>]
    (See note below about the previous names for this property in older Opera versions)</dd></dd>
    <dd><b class="l3heading">Inherited:</b> No</dd>
    <dd><b class="l3heading">Allowed Values:</b><br>
        - <b>None</b>: [DEFAULT] Do not use any link-source for this element.<br>
        - <b>Current</b>: Use the current '-o-set-link-source' value as the destination
          URL for this element.<br>
        - <b>Next</b>: Use the next '-o-set-link-source' value (as defined in
          document order?) as the destination URL for this element.</dd>
    <dd><b class="l3heading">Purpose:</b><br>
        Primarily used to set the usable activation target for a hyperlink in XML documents...<br>
        "This property sets the element to be a source anchor and, if so, declares
        which value of the 'link' variable that should be used: the current or the next."</dd>
</dl>

<big><b class="mainheading">Browser Peculiarities</b></big>
<ul>
    <li><b class="alert">Opera</b>
        <dl>
        <dd><b class="alert2">General:</b>
        <dd><dl>
            <dt>- Follow the bouncing ball: What will Opera call its proprietary 
                properties in the next version?<br> 
                Opera can't seem to make up its mind about what to call these properties. 
                With every new version they keep changing their names:
            <dt><b>-o-replace</b>:
                <dd>4.x-6.x: -replace; 7.x: -o-replace
            <dt><b>-o-use-link-source</b>:
                <dd>4.x: -link-use; 5.x: use-link-source; 6.x: -use-link-source; 7.x: -o-use-link-source
            <dt><b>-o-set-link-source</b>:
                <dd>4.x: -link-set; 5.x: set-link-source; 6.x: -set-link-source; 7.x: -o-set-link-source
            <dt>I wonder what they'll call them in the next version? ;-}
            </dl>
        <dd><b class="alert2">4.x:</b>
        <dd>- This version seems to double the height/width dimensions of any image
            I have tried so far using the '-replace' property. In 5.x+, the correct
            dimensions are used.
</ul>

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